Atmospheric glow discharge with concurrent coating deposition

ABSTRACT

A plasma is produced in a treatment space by diffusing a plasma gas at atmospheric pressure and subjecting it to an electric field created by two metallic electrodes separated by a dielectric material, a precursor material is mixed with the plasma, and a substrate film or web is coated by vapor deposition of the vaporized substance at atmospheric pressure in the plasma field. The deposited precursor is cured by electron-beam, infrared-light, visible-light, or ultraviolet-light radiation, as most appropriate for the particular material being-deposited. Plasma pre-treatment and post-treatment steps are used to enhance the properties of the resulting coated products. Similar results are obtained by atomizing and spraying the liquid precursor in the plasma field.

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Ser. No. 10/228,358,filed on Aug. 26, 2002, which is a continuation-in-part of Ser. No.09/660,003, filed on Sep. 12, 2000, now U.S. Pat. No. 6,441,553, acontinuation-in-part of Ser. No. 09/241,882, filed on Feb. 1, 1999,issued as U.S. Pat. No. 6,118,218.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to barrier films; in particular, theinvention relates to films and coatings with improved barriercharacteristics produced by combining precursor deposition andatmospheric glow-discharge plasma treatment with various curing stepsand pre- and/or post-deposition treatments tailored to optimize endresults specific to each particular applications.

2. Description of the Related Art

As detailed in U.S. Ser. No. 10/228,358, glow-discharge plasma treatmenthas been an effective method of treating surfaces to increase theirwettability and adhesion to various materials. Glow discharge provides auniform and homogenous plasma that produces a consistent surfacetreatment with high-energy electrons that collide with, dissociate andionize low-temperature neutrals, thereby creating highly reactive freeradicals and ions. These reactive species enable many chemical processesto occur with otherwise unreactive low-temperature feed stock andsubstrates. Based on these properties, low-density glow-dischargeplasmas are usually utilized for low material-throughput processesinvolving surface modification.

These plasmas are typically formed by partially ionizing a gas at apressure well below atmosphere. For the most part, these plasmas areweakly ionized, with an ionization fraction of 10⁻⁵ to 10⁻¹, establishedwith AC or DC power in systems with varied geometries. These systemsrequire vacuum chambers and pumps to maintain a very low pressure, whichincreases operating and maintenance costs. Accordingly, there has beenan extensive effort in recent years to develop plasma systems capable ofoperating at atmospheric pressure for surface treatment of polymerfilms, foils, and paper.

It is known that atmospheric plasma can be generated at relatively lowtemperatures. with a proper power source, the insertion of a dielectriclayer between the electrodes, and the use of an appropriate gas mixtureas the plasma medium. For surface treatment of polymer films, fabrics,paper, etc., atmospheric plasma can be established between twoelectrodes using an inert gas such as helium under particular operatingconditions. Usually one electrode is attached to a high voltage powersupply and a rotating drum is grounded and acts as the other electrode.One electrode is coated with a ceramic layer and the plasma gas isinjected between electrodes. Examples of such glow-discharge plasmasystems operating at atmospheric pressure are described in U.S. Pat.Nos. 5,387,842, 5,403,453, 5,414,324, 5,456,972, 5,558,843, 5,669,583,5,714,308, 5,767,469, and 5,789,145.

U.S. Pat. No. 6,118,218, incorporated herein by reference, disclosed aplasma treatment system capable of producing a steady glow discharge atatmospheric pressure with a variety of gas mixtures operating atfrequencies as low as 60 Hz. The invention consists of incorporating aporous metallic layer in one of the electrodes of a conventional plasmatreatment system. A plasma gas is injected into the electrode atsubstantially atmospheric pressure and allowed to diffuse through theporous layer, thereby forming a uniform glow-discharge plasma. As inprior-art devices, the material to be treated is exposed to the plasmacreated between this electrode and a second electrode covered by adielectric layer. Because of the micron size of the pores of the porousmetal, each pore also produces a hollow cathode effect that facilitatesthe ionization of the plasma gas. As a result, a steady-stateglow-discharge plasma is produced at atmospheric pressure and at powerfrequencies as low as 60 Hz. In order for the electrode holes to operateeffectively for producing an optimal glow discharge, their size mustapproach the mean free path of the plasma-gas at the system's operatingpressure.

U.S. Pat. No. 6,441,553, herein incorporated by reference, discloses afurther improvement in the art as a result of the discovery that theporous metallic layer of U.S. Pat. No. 6,118,218 may be used inconjunction with novel electrode arrangements to overcome thesubstrate-thickness limitations imposed by conventional plasma-treatmentapparatus. In an exemplary embodiment, the invention consists of twometallic electrodes embedded side by side in a dielectric medium havingan outer layer defining an exposed treatment space. One of theelectrodes is made of a porous metal and serves as a conduit forintroducing the plasma gas into the treatment space at substantiallyatmospheric pressure. The two electrodes are energized in conventionalmanner, using one of the electrodes as a ground, to create an electricfield between them and produce a uniform glow-discharge plasma in thetreatment space. Thus, the material to be treated can be exposed to theplasma so created without substantial limitation as to thickness,geometry and composition. By eliminating the need to maintain anelectric field across the substrate being treated, the electrodeassembly of the invention makes it possible to treat thick substratesand substrates of metallic composition that could not be treated withprior-art equipment. In addition, a powdery substrate can be treated byadding a shaker to a belt used to convey the substrate through theplasma field.

According to another advance in the use of atmospheric plasma disclosedin U.S. Pat. No. 6,441,553, herein incorporated by reference, vapordeposition is carried out in combination with plasma treatment byvaporizing a substance of interest, mixing it with the plasma gas, anddiffusing the mixture through the porous electrode. A heater is providedto maintain, if necessary, the temperature of the electrode above thecondensation temperature of the substance in order to prevent depositionduring diffusion. Thus, plasma treatment and vapor deposition arecarried out on a target substrate at the same time at atmosphericpressure.

The invention of U.S. Pat. No. 6,441,553 lies in the combination ofvapor deposition and plasma treatment at atmospheric pressure usingcertain classes of evaporable liquid and solid materials to producefilms and coatings with specifically improved barrier properties.Inasmuch as similar coatings have been produced using vapor depositionand plasma treatment under vacuum, many useful gases (i.e., vapors atambient conditions) and vaporizable constituents are known from theprior art that can also be used advantageously in theatmospheric-pressure process of the invention (such materials aretypically referred to as “precursors” in the art).

Copending U.S. Ser. No. 10/228,358, herein also incorporated byreference, provides a further development in the art of usingatmospheric-plasma treatment to improve conventional deposition andsurface treatment processes. A plasma gas at atmospheric pressure isused with various vapor precursors, such as silicon-based materials,fluorine-based materials, chlorine-based materials, and organo-metalliccomplex materials, to enable the manufacture of coated substrates withimproved properties with regard to moisture-barrier, oxygen-barrier,hardness, scratch- and abrasion-resistance, chemical-resistance,low-friction, hydrophobic and/or oleophobic, hydrophilic, biocide and/orantibacterial, and electrostatic-dissipative/conductive characteristics.

The present invention is the result of further developments in the art.It discloses various atmospheric techniques wherein plasma treatment iscombined with precursor deposition and other process steps common in theart, such as curing with ultraviolet, visible, or infrared light,electron-beam radiation, and pre- and/or post-deposition plasmatreatment of the product.

BRIEF SUMMARY OF THE INVENTION

The gist of this invention is in the combination of the atmosphericplasma process originally rendered possible by the invention disclosedin U.S. Pat. No. 6,118,218 with various other steps known in the art ofvacuum deposition in order to further improve the quality of theproducts obtained through atmospheric plasma processes. In particular,the invention is directed at the atmospheric-pressure manufacture offilms and sheets (coating layers, in general) with improved barrierproperties to moisture and oxygen for use in packaging, displays andelectronic applications wherein the process of manufacture includescuring of the deposited precursor layers by exposure to UV light, orvisible light, infrared light, electron-beam radiation, and theadditional steps of plasma pre-and/or post-treatment.

Therefore, the invention consists of producing a plasma in a treatmentspace by passing a plasma gas through a porous layer and subjecting itto an electric field produced by two metallic electrodes separated by adielectric material, and by coating a substrate material by vapordeposition or atomized spraying at atmospheric pressure in the plasmafield. According to one aspect of the invention, the deposited precursoris cured by exposure to ultraviolet light in the presence of aphotoinitiator, followed by further plasma treatment to enhance curingand to smooth the coated surface. The substrate may also be pre-treatedin a separate plasma field to improve adhesion of the precursor layer.

In another embodiment of the invention, the substrate is firstpre-treated with a plasma gas to clean the surface, a precursor isdeposited in a plasma field at atmospheric pressure, and the depositedlayer is cured by exposure to visible light in the presence of aphotoinitiator. The coating is then post-treated with a plasma gas toenhance curing and smoothness. In another embodiment, the precursor filmformed by vapor deposition is cured with an electron beam and is furtherpost-treated with a plasma gas to enhance its finished properties. Inyet another embodiment, the curing stage is accomplished with aninfrared light, followed by further plasma treatment to enhance curingand to smooth the coated surface.

According to another aspect of the invention, the precursor is atomizedand sprayed, rather than vapor deposited, over the substrate in thepresence of a plasma field. Various precursors so deposited are thenalternatively cured using UV light, IR light, visible light, or anelectron-beam gun, depending on the desired finished properties, as inthe case of vapor deposited precursors.

Various other purposes and advantages of the invention will become clearfrom its description in the specification that follows and from thenovel features particularly pointed out in the appended claims.Therefore, to the accomplishment of the objectives described above, thisinvention consists of the features hereinafter illustrated in thedrawings, fully described in the detailed description of the preferredembodiment and particularly pointed out in the claims. However, suchdrawings and description disclose only some of the various ways in whichthe invention may be practiced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation of a conventional plasma-treaterconfiguration.

FIG. 2 is a partially cut-out, side sectional view of an electrodecontaining a porous-metal component according to the invention.

FIG. 3 is a schematic representation of an electrode assembly accordingto the invention wherein a porous-metal structure is used as anelectrode as well as a perfusion medium in side-by-side combination witha conventional electrode encased in a dielectric medium.

FIG. 4 is a schematic view of an evaporator used to practice thecombined vapor-deposition and plasma-treatment processes of theinvention at atmospheric pressure.

FIG. 5 is a schematic view of the plasma treater configuration of FIG. 1incorporating the evaporator of FIG. 4 for atmospheric treatmentaccording to the invention by mixing plasma gas and coating precursorprior to injection through the electrode.

FIG. 6 is a schematic view of the plasma treater configuration of FIG.5, wherein the coating precursor is injected directly over substrateprior to plasma treatment.

FIG. 7 is a schematic representation of an atmospheric vapor depositionsystem according to the invention, wherein the steps of plasmapre-treatment, vapor deposition, monomer curing, and plasmapost-treatment are carried out successively in line over a movingsubstrate.

FIG. 8 is a schematic representation of an atmospheric deposition systemas illustrated in FIG. 7, wherein the liquid precursor is atomized anddeposited by spraying it over the moving substrate.

FIG. 9 is a schematic illustration of a water-cooled electrode used todiffuse plasma gas according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

This invention utilizes the advantages produced by the plasma-treatmentelectrodes disclosed in U.S. Ser. No. 09/660,003 and U.S. Pat. No.6,118,218 to improve the surface properties of coated substratesmanufactured by plasma-enhanced vapor deposition at atmosphericpressure. Accordingly, the invention may be carried out using thevarious embodiments of the apparatus described in those disclosures,which are herein incorporated by reference in their entirety. Inaddition, the present invention utilizes various curing andplasma-treatment units operated in line with those described in thereferenced patents.

Referring to the drawings, wherein like parts are designated throughoutwith like numerals and symbols, FIG. 1 shows a general layout of anatmospheric plasma treater assembly wherein a plasma treater 10 is shownmounted opposite to the roller 12 of a conventional web-treatmentsystem. A web or film 14 of material to be treated is passed through theassembly between the plasma treater and the roller at speeds typicallyranging from 1 to 200 meter/min. The roller 12 is grounded and coatedwith a dielectric material 16, such as polyethylene teraphthalate (PET).The plasma treater 10 contains at least one electrode as described inU.S. Pat. No. 6,118,218, which is connected, through a cable 18, to anAC power supply 20 operating at any frequency between 60 Hz and themaximum frequency available from the power supply. The treater 10 isheld in place conventionally by a holding bracket 22 to maintain adistance of 1-2 mm between the dielectric layer 16 and the treater 10.Plasma gas, such as helium, argon, and mixtures of an inert gas withnitrogen, oxygen, air, carbon dioxide, methane, acetylene, propane,ammonia, or mixtures thereof, can be used with this treater to sustain auniform and steady plasma at atmospheric pressure. The gas is suppliedto the treater 10 through a manifold 24 that feeds the porous electrodeof the invention.

As shown in FIG. 2, an embodiment of a porous electrode 30 incorporatedwithin the treater 10 consists of a hollow housing 32 with a porousmetal layer 34 having pores sized to approximate the mean free path ofthe plasma gas intended to be used in the treater. The gas is fed to theupper portion 36 of the hollow electrode 30 at substantially atmosphericpressure through an inlet pipe 38 connected to the exterior manifold 24.Similarly, the electrode is energized by an electrical wire 40 connectedto the power system through the exterior cable 18. The electrode 30preferably includes a distribution baffle 42 containing multiple,uniformly spaced apertures 44 designed to distribute the gas uniformlythroughout the length of the bottom portion 46 of the hollow electrode30.

In the alternative, any one of several side-by-side embodiments of aporous electrode can be used to practice the invention, as disclosed inU.S. Pat. No. 6,441,553 and exemplified herein in FIG. 3. Such anelectrode unit 50 may consist, for example, of a pair of electrodesencased in a dielectric housing 52, such as a ceramic structure. Afirst, conventional electrode 54 is coupled to a porous electrode 56made of the same type of porous material described in. U.S. Pat. No.6,118,218. The two electrodes are placed side by side facing the processspace 58 where a target substrate is intended to be treated. Theelectrode assembly 50 is energized by an AC power source 20 and groundedthrough a ground 60 in conventional manner using either electrode as theground. An inlet port 62 is connected to the porous electrode 56 to feedthe plasma gas to the unit 50 through the porous metal constituting theelectrode. The dielectric housing 52 between the porous electrode 56 andthe boundary of the process space 58 may also include a dielectric layer64 that consists of a porous portion capable of diffusing plasma gasreceived from the porous electrode into the process space.Alternatively, the porous dielectric layer 64 may be used with a hollowelectrode 56 (instead of a porous electrode 56) for diffusing the plasmagas into the process space 58.

As a result of this configuration, an electric field is produced acrossthe process space 58 when the electrode pair 54,56 is energized inconventional manner. The plasma gas is diffused at substantiallyatmospheric pressure through the porous electrode 56 and the dielectriclayer 64 into the process space 58 where the electric field produces asteady-state glow-discharge plasma at power frequencies as low as 60 Hz.For best results, the sides 66 and 68 of the two electrodes facing theprocess space are substantially aligned with the exposed surface 70 ofthe porous dielectric layer 64, thereby promoting coupling of the twoelectrodes and producing an electric field across the process spacealong a plane aligned with the sides 66,68. Using this side-by-sideembodiment of the invention, the treatment space 58 can be expandedwithout limitations imposed by the need to establish an electric fieldbetween the electrode and a grounded roller 12, as was the case prior tothe invention disclosed in Ser. No. 09/660,003.

In order to practice the present invention, the treater assembly of FIG.1 is preferably coupled to an evaporator 80, such as illustratedseparately in FIG. 4, in order to provide the capability of evaporatingliquid and solid precursors. The coating precursor to be deposited byvapor deposition on a given substrate is fed to the evaporator 80through an inlet port 82 and is heated to its evaporation temperature byheating bands 84 at the bottom of the evaporator. If a gaseous precursoris being used, it passes through the unit without effect (or it may bepassed through a bypass channel and injected directly into the plasmaarea). If a solid precursor is being used, it is liquefied prior tofeeding it to the evaporator 80. Plasma gas is also supplied to theevaporator through a separate port 86 and is mixed with the gas orvaporized material prior to being fed to the electrode (30, 50 orequivalent porous electrode) through an outlet duct 88. FIG. 5 shows thecombination of the evaporator 80 with a plasma-treatment unit of thetype illustrated in FIG. 1, wherein the flow rate of, theprecursor/plasma-gas mixture to the electrode is controlled by aflowmeter 90 and the flow rates of the precursor and plasma gas into theevaporator 80 are regulated by additional appropriate flowmeters 92 and94, respectively.

As illustrated schematically with reference to the embodiment 50 of FIG.3, a heater element 96 may also be used around the porous electrode tomaintain the vaporized state of any liquid or solid precursor used inthe process while the gas/vapor mixture is diffused through the porouselectrode 56 (or equivalent electrode). As would be clear to one skilledin the art, the heater 96 must be capable of maintaining the electrodetemperature uniformly above the vaporization temperature of thedeposition material at atmospheric pressure. A temperature range from70° C. to 100° C. has been found to be sufficient for most materials ofinterest. It is noted that the use of a side-by-side electrode enablesplasma treatment without a dielectric coating 16 over the drum 12.

In an alternative embodiment of the invention, the evaporator 80 is usedonly to evaporate the precursor material, if necessary, separately fromthe plasma gas. The evaporated material is then injected directly in thevicinity of the plasma field, as illustrated in FIG. 6, prior to passingthe substrate through the process space between the plasma treater 10and the drum 12. The precursor vapor is injected through a slittednozzle 98 placed across the drum 12, such that the vapor is directed fordeposition toward the substrate 14 under the influence of the plasmafield created by the treater 10. The plasma gas is injected separatelythrough the porous electrode in the treater 10 to provide the plasmafield in the process space.

According to still another embodiment if the invention suitable for thedeposition of liquid precursors, the precursor is atomized and sprayedonto the substrate as it passes through the plasma field. Surprisingly,so long as the particle size of the atomized liquid permits theformation of a liquid film of desired thickness over the substrate, theeffect of the plasma field and the subsequent curing by the same methodsutilized with vapor deposition produce comparable results.

The present invention contemplates additional steps to improve adhesionand smoothness in the finished product. Accordingly, several treatmentunits are combined in line in a single system 100, as illustratedschematically in FIG. 7, to afford the versatility required to tailoreach deposition process to the requirements of the finished product. Thesystem 100, comprises a first conventional plasma-treatment unit 102used to clean the surface of the web or other substrate 14 being coatedwhile it passes continuously over the drum 12 from a feed roller 104 toa take-up roller 106. The plasma pre-treatment is used conventionally toclean the surface of the substrate to improve adhesion by removingmoisture and other small molecules. A combined vapor-deposition/plasmaunit 108 is then used, in the configuration detailed in either FIG. 5 orFIG. 6, to deposit a vaporized precursor as detailed in U.S. Ser. No.10/228,358. A precursor source 110 may be incorporated into or used inconjunction with the plasma unit 108. In addition, a curing station 112is used after the vapor deposition to polymerize the precursor and forma solid film over the substrate 14. The station 112 may consist of aninfrared lamp, an electron-beam unit, an ultraviolet lamp, or a visiblelight source. In the last two cases, an appropriate photoinitiator isadded to the precursor prior to vaporization. Finally, anotherplasma-treatment unit 114 is used to enhance curing and to smooth thesurface of the coating film. In another embodiment of the inventionillustrated in FIG. 8, the precursor is atomized, rather than vaporized,and sprayed onto the plasma-treated surface through a nozzle 120.

Organic substrates such as polypropylene, polyethylene, and polyethyleneteraphthalate of various thickness were coated according to theinvention using various materials with desirable properties for specificobjectives. For instance, polyester substrates were coated by vapordeposition in a helium plasma at atmospheric pressure using vaporizedsilicon-based materials (e.g., siloxanes, alkyl silanes, silazanes, andsilsesquioxanes) mixed with the plasma-gas stream and diffused into thetreatment area. The resulting products exhibited improved surfaceproperties with regard to moisture- and oxygen-barrier characteristics,hardness, scratch and abrasion resistance, chemical resistance, and lowfriction. The same plasma gases and fluoro-silicones were also used forvapor deposition under the same conditions by separate injection(through a slitted nozzle) and deposition over the substrate, followedby plasma treatment by passing the substrate through the treater wherethe plasma gas was diffused separately into the process space. Similarlypositive results were obtained with fluorine-based precursors (e.g.,fluorocarbons, fluoro-silicones) to provide hydrophobic and/oroleophobic properties. Chlorine-based precursors (e.g., chloro-carbons,chloro-silicones) were used to produce biocide (including antibacterial)and barrier properties; and organo-metallic complex precursors (e.g.,silver, copper, boron or aluminum complex) were used to produceelectrostatic, dissipative, conductive, biocidal and barrier properties.

Thus, according to the invention, the substrate is preferablypre-treated with a plasma gas in order to clean its surface, it iscoated with a precursor, the deposited layer is cured according to amost appropriate method for the particular application, and anadditional plasma treatment is utilized to complete curing and furtherimprove the properties of the finished product. The following examplesillustrate the combination of process steps that characterize theinvention. All tests reported below are representative of many moresimilar tests carried out with the same materials using a helium plasmagas and a precursor in proportions varying from 10 to 98% y volume ofplasma gas (about 90% plasma gas being preferred, the balance beingvapor precursor). The plasma gas and the vapor precursor were fed to thetreater (together or separately, as described above with reference toFIGS. 5 and 6) at a combined rate varying from about 100 to about 10,000sccm (standard cubic centimeters per minute). In the case of atomizedprecursor, it was fed into the plasma gas at a rate of about 100 ml/sec(atomized) in about 500 to about 1000 sccm of plasma gas. The electrodeassembly operated with a porous component with average pore size in therange of 1-20 microns. The substrate material to be treated was passedthrough the treatment space of 12-inch plasma treaters facing aconventional rotating drum. The tests were conducted at frequenciesranging from about 20 KHz to about 13.5 MHz.

EXAMPLE 1

Plasma Pre-Treatment; UV-Light Curing; Plasma Post-Treatment

-   Substrate material: PET film-   Drum Speed: 200 ft/min-   Pre-treatment:-   Plasma gas: helium fed at 2000 sccm-   AC-voltage frequency: 20 KHz-   Deposition:-   Precursor: liquid fluoroacrylate monomer (with 5% Irgacure-184    photoinitiator)-   Evaporator temperature: 200-250 ° C.-   Mixing step: mixed with plasma gas prior to injection-   Feed rate of vaporized precursor: 200 sccm-   Plasma gas: helium fed at 2000 sccm-   AC-voltage frequency: 20 KHz-   Curing:-   Low Pressure Mercury UV Lamp at 300 Watt/inch-   Post-Treatment:-   Plasma gas: helium with 5% acetylene fed at 100 sccm-   AC-voltage frequency: 15 KHz.

The resulting coated product exhibited hydrophobic and oleophobicproperties with excellent adhesion to the substrate. Similar resultswere obtained when polypropylene, polyethylene, polycarbonate,polyamide, polyimide and cellulose derivative films were treated/coatedaccording to Example 1. The same experiment was repeated with paper andfabrics (woven and nonwoven). Similar hydrophobicity and oleophobicitywere obtained. Other precursors, such as perfluoropolyethylene glycolsand fluorinated alcohols, were tested and-showed the same results.

EXAMPLE 2

Plasma Pre-Treatment; UV-Light Curing; Plasma Post-Treatment

-   Substrate material: PET film-   Drum Speed: 200 ft/min-   Pre-treatment:-   Plasma gas: helium with 10% oxygen fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Deposition:-   Precursor: liquid fluoroacrylate monomer (with 5% Irgacure-184    photoinitiator)-   Evaporator temperature: 200-250° C.-   Mixing step: mixed with plasma gas prior to injection-   Feed rate of vaporized precursor: 100 sccm-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Curing:-   Low Pressure Mercury UV Lamp at 300 Watt/inch-   Post-Treatment:-   Plasma gas: helium with 5% acetylene fed at 100 sccm-   AC-voltage frequency: 15 KHz

The resulting coated product exhibited hydrophobic and oleophobicproperties with excellent adhesion to the substrate.

EXAMPLE 3

Plasma Pre-Treatment; UV-Light Curing; Plasma Post-Treatment

-   Substrate material: PET film-   Drum Speed: 200 ft/min-   Pre-treatment:-   Plasma gas: helium fed at 2000 sccm-   AC-voltage frequency: 20 KHz-   Deposition:-   Precursor: liquid polyethyleneglycol monoacrylate (with 5%    Irgacure-184 photoinitiator)-   Evaporator temperature: 200-250° C.-   Mixing step: mixed with plasma gas prior to injection-   Feed rate of vaporized precursor: 200 sccm-   Plasma gas: helium fed at 2000 sccm-   AC-voltage frequency: 20 KHz-   Curing:-   Low Pressure Mercury UV Lamp at 300 Watt/inch-   Post-Treatment:-   Plasma gas: helium with 5% acetylene fed at 3000 sccm-   AC-voltage frequency: 15 KHz

The resulting coated product exhibited hydrophilic and anti-fogproperties with excellent adhesion to the substrate. Similar resultswere obtained when polypropylene, polyethylene, polycarbonate,polyamide, polyimide and cellulose derivative films were treated/coatedaccording to Example 3. The same experiment was repeated with paper andfabrics (woven and nonwoven) and similar hydrophilicity and anti-fogproperties were obtained.

EXAMPLE 4

Plasma Pre-Treatment; UV-Light Curing; Plasma Post-Treatment

-   Substrate material: PET film-   Drum Speed: 200 ft/min-   Pre-treatment:-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Deposition:-   Precursor: liquid acrolin and/or chlorinated acrylate with 5%    Irgacure-184 photoinitiator)-   Evaporator temperature: 200-250° C.-   Mixing step: mixed with plasma gas prior to injection-   Feed rate of vaporized precursor: 200 sccm-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Curing:-   Low Pressure Mercury UV Lamp at 300 Watt/inch-   Post-Treatment:-   Plasma gas: helium with 5% acetylene fed at 3000 sccm-   AC-voltage frequency: 15 KHz

The resulting coated product exhibited biocide, anti-bacterialproperties with excellent adhesion to the substrate. Similar resultswere obtained when polypropylene, polyethylene, polycarbonate,polyamide, polyimide and cellulose derivative films were treated/coatedaccording to Example 4. The same experiment was repeated with paper andfabrics (woven and nonwoven) and similar biocide properties wereobtained.

EXAMPLE 5

Plasma Pre-Treatment; Visible-Light Curing; Plasma Post-Treatment

-   Substrate material: PET film-   Drum Speed: 200 ft/min.-   Pre-treatment:-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Deposition:-   Precursor: liquid fluoroacrylate monomer (with 5% H-NU-635    photoinitiator)-   Evaporator temperature: 200-250° C.-   Mixing step: mixed with plasma gas prior to injection-   Feed rate of vaporized precursor: 200 sccm-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Curing:-   Tungsten-Halogen Lamp at 100 Watt/inch-   Post-Treatment:-   Plasma gas: helium with 5% acetylene fed at 3000 sccm-   AC-voltage frequency: 20 KHz

The resulting coated product exhibited hydrophobic and oleophobicproperties with excellent adhesion to the substrate.

EXAMPLE 6

Plasma Pre-Treatment; Visible-Light Curing; Plasma Post-Treatment

-   Substrate material: PET film-   Drum Speed: 200 ft/min-   Pre-treatment:-   Plasma gas: helium with 10% oxygen fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Deposition:-   Precursor: liquid fluoroacrylate monomer (with 5% H-NU-635    photoinitiator)-   Evaporator temperature: 200-250° C.-   Mixing step: mixed with plasma gas.prior to injection-   Feed rate of vaporized precursor: 200 sccm-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Curing:-   Tungsten-Halogen Lamp at 100 Watt/inch-   Post-Treatment:-   Plasma gas: helium with 5% acetylene fed at 3000 sccm-   AC-voltage frequency: 15 KHz

The resulting coated product exhibited hydrophobic and oleophobicproperties with excellent adhesion to the substrate.

EXAMPLE 7

Plasma Pre-Treatment; Visible-Light Curing; Plasma Post-Treatment

-   Substrate material: PET film-   Drum Speed: 200 ft/min-   Pre-treatment:-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Deposition:-   Precursor: liquid polyethyleneglycol monoacrylate (with 5% H-NU-635    photoinitiator)-   Evaporator temperature: 200-250° C.-   Mixing step: mixed with plasma gas prior to injection-   Feed rate of vaporized precursor: 200 sccm-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Curing:-   Tungsten-Halogen Lamp at 100 Watt/inch-   Post-Treatment:-   Plasma gas: helium with 5% acetylene fed at 3000 sccm-   AC-voltage frequency: 15 KHz

The resulting coated product exhibited hydrophilic and anti-fogproperties with excellent adhesion to the substrate.

EXAMPLE 8

Plasma Pre-Treatment; Visible-Light Curing; Plasma Post-Treatment

-   Substrate material: PET film-   Drum Speed: 200 ft/min-   Pre-treatment:-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Deposition:-   Precursor: liquid acrolin and/or chlorinated acrylate with 5%    H-NU-635 photoinitiator)-   Evaporator temperature: 200-250° C.-   Mixing step: mixed with plasma gas prior to injection-   Feed rate of vaporized precursor: 200 sccm-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Curing:-   Tungsten-Halogen Lamp at 100 Watt/inch-   Post-Treatment:-   Plasma gas: helium with 5% acetylene fed at 3000 sccm-   AC-voltage frequency: 15 KHz

The resulting coated product exhibited biocide, anti-bacterialproperties with excellent adhesion to the substrate.

EXAMPLE 9

Plasma Pre-Treatment; IR-Light Curing; Plasma Post-Treatment

-   Substrate material: PET film-   Drum Speed: 20 ft/min-   Pre-treatment:-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Deposition:-   Precursor: liquid fluoroacrylate monomer-   Evaporator temperature: 200-250° C.-   Mixing step: mixed with plasma gas prior to injection-   Feed rate of vaporized precursor: 200 sccm-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Curing:-   Infrared Lamp at 500 Watt-   Post-Treatment:-   Plasma gas: helium with 5% acetylene fed at 3000 sccm-   AC-voltage frequency: 15 KHz

The resulting coated product exhibited hydrophobic and oleophobicproperties with excellent adhesion to the substrate.

EXAMPLE 10

Plasma Pre-Treatment; IR-Light Curing; Plasma Post-Treatment

-   Substrate material: PET film-   Drum Speed: 20 ft/min-   Pre-treatment:-   Plasma gas: helium with 10% oxygen fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Deposition:-   Precursor: liquid fluoroacrylate monomer-   Evaporator temperature: 200-250° C.-   Mixing step: mixed with plasma gas prior to injection-   Feed rate of vaporized precursor: 200 sccm-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Curing:-   Infrared Lamp at 500 Watt-   Post-Treatment:-   Plasma gas: helium with 5% acetylene fed at 3000 sccm-   AC-voltage frequency: 15 KHz

The resulting coated product exhibited hydrophobic and oleophobicproperties with excellent adhesion to the substrate.

EXAMPLE 11

Plasma Pre-Treatment; IR-Light Curing; Plasma Post-Treatment

-   Substrate material: PET film-   Drum Speed: 20 ft/min-   Pre-treatment:-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Deposition:-   Precursor: liquid polyethyleneglycol monoacrylate-   Evaporator temperature: 200-250° C.-   Mixing step: mixed with plasma gas prior to injection-   Feed rate of vaporized precursor: 200 sccm-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Curing:-   Infrared Lamp at 500 Watt-   Post-Treatment:-   Plasma gas: helium with 5% acetylene fed at 3000 sccm-   AC-voltage frequency: 15 KHz

The resulting coated product exhibited hydrophilic and anti-fogproperties with excellent adhesion to the substrate.

EXAMPLE 12

Plasma Pre-Treatment; IR-Light Curing; Plasma Post-Treatment

-   Substrate material: PET film-   Drum Speed: 20 ft/min-   Pre-treatment:-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Deposition:-   Precursor: liquid acrolin and/or chlorinated acrylate-   Evaporator temperature: 200-250° C.-   Mixing step: mixed with plasma gas prior to injection-   Feed rate of vaporized precursor: 200 sccm-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Curing:-   Infrared Lamp at 500 Watt-   Post-Treatment:-   Plasma gas: helium with 5% acetylene fed at 3000 sccm-   AC-voltage frequency: 15 KHz

The resulting coated product exhibited biocide, anti-bacterialproperties with excellent adhesion to the substrate.

EXAMPLE 13

Plasma Pre-Treatment; Electron-Beam Curing; Plasma Post-Treatment

-   Substrate material: PET film-   Drum Speed: 200 ft/min-   Pre-treatment:-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Deposition:-   Precursor: liquid fluoroacrylate monomer-   Evaporator temperature: 200-250° C.-   Mixing step: mixed with plasma gas prior to injection-   Feed rate of vaporized precursor: 200 sccm-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Curing:-   Electrocurtain (Energy Science, Inc.)-   Post-Treatment:-   Plasma gas: helium with 5% acetylene fed at 3000 sccm-   AC-voltage frequency: 15 KHz

The resulting coated product exhibited hydrophobic and oleophobicproperties with excellent adhesion to the substrate.

EXAMPLE 14

Plasma Pre-Treatment; Electron-Beam Curing; Plasma Post-Treatment

-   Substrate material: PET film-   Drum Speed: 200 ft/min-   Pre-treatment:-   Plasma gas: helium with 10% oxygen fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Deposition:-   Precursor: liquid fluoroacrylate monomer-   Evaporator temperature: 200-250° C.-   Mixing step: mixed with plasma gas prior to injection-   Feed rate of vaporized precursor: 200 sccm-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Curing:-   Electrocurtain (Energy Science, Inc.)-   Post-Treatment:-   Plasma gas: helium with 5% acetylene fed at 3000 sccm-   AC-voltage frequency: 15 KHz

The resulting coated product exhibited hydrophobic and oleophobicproperties with excellent adhesion to the substrate.

EXAMPLE 15

Plasma Pre-Treatment; Electron-Beam Curing; Plasma Post-Treatment

-   Substrate material: PET film-   Drum-Speed: 200 ft/min-   Pre-treatment:-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Deposition:-   Precursor: liquid polyethyleneglycol monoacrylate-   Evaporator temperature: 200-250° C.-   Mixing step: mixed with plasma gas prior to injection-   Feed rate of vaporized precursor: 200 sccm-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Curing:-   Electrocurtain (Energy Science, Inc.)-   Post-Treatment:-   Plasma gas: helium with 5% acetylene fed at 3000 sccm-   AC-voltage frequency: 15 KHz Curing:

The resulting coated product exhibited hydrophilic and anti-fogproperties with excellent adhesion to the substrate.

EXAMPLE 16

Plasma Pre-Treatment; Electron-Beam Curing; Plasma Post-Treatment

-   Substrate material: PET film-   Drum Speed: 200 ft/min-   Pre-treatment:-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 KHz-   Deposition:-   Precursor: liquid acrolin and/or chlorinated acrylate-   Evaporator temperature: 200-250° C.-   Mixing step: mixed with plasma gas prior to injection-   Feed rate of vaporized precursor: 200 sccm-   Plasma gas: helium fed at 3000 sccm-   AC-voltage frequency: 20 kHz-   Curing:-   Electrocurtain (Energy Science, Inc.)-   Post-Treatment:-   Plasma gas: helium with 5% acetylene fed at 3000 sccm-   AC-voltage frequency: 15 KHz

The resulting coated product exhibited biocide, anti-bacterialproperties with excellent adhesion to the substrate.

Similar results were obtained by injecting the vaporized precursordirectly into the plasma filed, rather than mixing it with the plasmagas prior to injection. A similar set of tests was also performed usinga liquid atomizer, as illustrated schematically in FIG. 8, rather thanan atmospheric vapor deposition system. The results were surprisinglysimilar to the ones achieved in Examples 1-16. The photoinitiators weremixed and atomized with the liquid precursors and, after deposition,they were cured using the same various treatment steps illustratedabove.

In some instances, a water cooled electrode, as illustrated in FIG. 9,was used in the production of the plasma field. This enabled theapplication of greater power to the system. In operation, such anelectrode 130 is oriented so that its curved surface 132 faces theprocess space and the grounded process drum. A plasma gas blanket isestablished in the plasma region below the curved surface 132 by feedingplasma gas into porous diffusion channels 134. Cooling is established bypumping coolant through cooling channels 136. Dielectric barrier plates140 are affixed to the outer surface of the electrode to providecontainment of the plasma gas at the exterior surface of the electrodeassembly. The electrode is electrified with a high voltage source and apartial discharge is generated immediately below the dielectric surface138. A substrate to be treated is transported in conventional mannerthrough the plasma region on the outer surface of the grounded processdrum.

These data show that the invention advantageously enables the productionof plasma-enhanced coated substrates at atmospheric-pressure conditionswith properties equal to or better than previously obtained under vacuumplasma conditions. These results show that the electrodes of theinvention can be used for treating and modifying the surface propertiesof organic as well as inorganic substrates without vacuum equipment ormaterial-thickness limitations. In addition, they demonstrate thatdeposited precursors may be cured by alternative means with theappropriate addition of photoinitiators, as well understood in the art,in order to tailor the treatment and the application to specific desiredresults.

Based on their known properties, it is anticipated that a large varietyof other polymerizable compounds can be used as precursors with thisinvention. They include the following:

1. Unsaturated alcohols and esters thereof: allyl, methallyl,1-choroallyl, 2-chloroallyl, vinyl, methylvinyl, 1-phenalallyl, andbutenyl alcohols; and esters of such alcohols with saturated acids suchas acetic, propionic, and butyric; with unsaturated acids such asacrylic, α-substituted acrylic (including alkylacrylic, such asmethacrylic, ethylacrylic, propylacrylic, etc.; and arylacrylic, such asphenylacrylic), crotonic, oleic, linoeic and linolenic, and withpolybasic acids, such as oxalic, and malonic.

2. Unsaturated acids (as listed above for example); and esters thereofwith lower saturated alcohols, such as methyl, ethyl propyl, isopropyl,butyl, isobutyl, sec-butyl, tert-butyl, 2-ethylhexyl, and cyclohexylalcohols; and with saturated lower polyhydric alcohols, such as ethyleneglycol, propylene glycol, tetramethylene glycol, neopentyl glycol, andtrimethylopropane.

3. Unsaturated lower polyhydric alcohols, such as butenediol; and estersthereof with saturated and unsaturated aliphatic and aromatic, monobasicand polybasic acids, such as illustrated above.

4. Esters of the above-described unsaturated acids, especially acrylicand methacrylic acids, with higher molecular-weight monohydroxy andpolyhydroxy materials, such as decyl alcohol, isodecyl alcohol, oleylalcohol, and stearyl alcohol.

5. Vinyl cyclic compounds including styrene, o-, m-, p-chlorostyrenes,bromostyrenes, fluorostyrens, methylstyrenes, ethylstyrenes,cyanostyrenes; di-, tri-, and tetrachlorostyrenes, bromostyrenes,fluorostyrenes, methylstyrenes, ethylstyrenes, cyanostyrenes,vinylnaphthalene, vinylcyclohexane, divinylbenzene, trivinylbenzene;allybenzene, and heterocycles-such as vinylfuran, vinnylpridine,vinylbenzofuran, N-vinylcarbazole, N-vinylpyrrolidone, andN-vinyloxazolidone.

6. Unsaturated ethers, such as methyl vinyl ether, ethyl vinyl ether,cyclohexyl vinyl ether, octyl vinyl ether, diallyl ether, ethylmethallyl ether, and allyl ethyl ether.

7. Unsaturated ketones, such as methyl vinyl ketone and ethyl vinylketone.

8. Unsaturated amides, such as acrylamide, methacrylamide,N-methylacrylamide, N-phenylolacrylamide, N-allylacrylamide,N-methylolacrylamide, N-allylcaprolactam, diacetone acrylamide, and2-acrylamido-2-methylpropanesulfonic acid.

9. Unsaturated aliphatic hydrocarbons, such as ethylene, acetylene,propylene, butanes, butadiene, isoprene, and 2-chlorobutadiene.

10. Unsaturated alky halides, such as vinyl fluoride, vinyl chloride,vinyl bromide, nylidene bromide, allyl chloride, and ally bromide.

11. Unsaturated acid anhydrides, such as maleic, citraconic, itaconic,cis-4-cyclohexene-1,2-dicarboxylic, andbicyclo(2.2.1)-5-heptene-2,3-dicarboxylic anhydrides.

12. Unsaturated acid halides, such as cinnamyl acrykyl, methacrylyl,crontonyl, oleyl, and fumaryl chlorides or bromides.

13. Unsaturated nitrites, such as acrylonitriles, methacrylonitrile, andother substituted acrylonitriles.

Various changes in the details, steps and components that have beendescribed may be made by those skilled in the art within the principlesand scope of the invention herein illustrated and defined in theappended claims. Therefore, while the present invention has been shownand described herein in what is believed to be the most practical andpreferred embodiments, it is recognized that departures can be madetherefrom within the scope of the invention, which is not to be limitedto the details disclosed herein but is to be accorded the full scope ofthe claims so as to embrace any and all equivalent processes andproducts.

1. A method for manufacturing a coated substrate by a process of vapordeposition and concurrent glow-discharge plasma treatment atsubstantially atmospheric pressure, comprising the following steps:providing a first electrode and a second electrode separated by adielectric material and facing a process space: applying a voltageacross-the electrodes; mixing a vaporized precursor with a plasma gas;diffusing the vaporized precursor and plasma gas through a porousmaterial into the process space at substantially atmospheric pressure;depositing the vaporized precursor over said substrate; and curing theprecursor to produce a polymeric film.
 2. The method of claim 1, whereinsaid curing step is carried out with ultraviolet radiation.
 3. Themethod of claim 1, wherein said curing step is carried out with visiblelight.
 4. The method of claim 1, wherein said curing step is carried outwith infrared radiation.
 5. The method of claim 1, wherein said curingstep is carried out with electron-beam radiation.
 6. The method of claim1, further including the step of pre-treating the substrate in a plasmafield prior to the step of depositing the vaporized precursor.
 7. Themethod of claim 1, further including the step of post-treating thesubstrate in a plasma field after the step of depositing the vaporizedprecursor.
 8. The method of claim 6, further including the step ofpost-treating the substrate in a plasma field after the step ofdepositing the vaporized precursor.
 9. The method of claim 8, whereinsaid curing step is carried out with ultraviolet radiation.
 10. Themethod of claim 8, wherein said curing step is carried out with visiblelight.
 11. The method of claim 8, wherein said curing step is carriedout with infrared radiation.
 12. The method of claim 8, wherein saidcuring step is carried out electron-beam radiation.
 13. A method formanufacturing a coated substrate by a process of vapor deposition andconcurrent glow-discharge plasma treatment at substantially atmosphericpressure, comprising the following steps: providing a first electrodeand a second electrode separated by a dielectric material and facing aprocess space: applying a voltage across the electrodes; diffusing aplasma gas through a porous material into the process space atsubstantially atmospheric pressure; mixing a vapor precursor with theplasma gas in the process space; depositing the vaporized precursor oversaid substrate; and curing the precursor to produce a polymeric film.14. The method of claim 13, wherein said curing step is carried out withultraviolet radiation.
 15. The method of claim 13, wherein said curingstep is carried out with visible light.
 16. The method of claim 13,wherein said curing step is carried out with infrared radiation.
 17. Themethod of claim 13, wherein said curing step is carried outelectron-beam radiation.
 18. The method of claim 13, further includingthe step of pre-treating the substrate in a plasma field prior to thestep of depositing the vaporized precursor.
 19. The method of claim 13,further including the step of post-treating the substrate in a plasmafield after the step of depositing the vaporized precursor.
 20. Themethod of claim 18, further including the step of post-treating thesubstrate in a plasma field after the step of depositing the vaporizedprecursor.
 21. The method of claim 20, wherein said curing step iscarried out with ultraviolet radiation.
 22. The method of claim 20,wherein said curing step is carried out with visible light.
 23. Themethod of claim 20, wherein said curing step is carried out withinfrared radiation.
 24. The method of claim 8, wherein said curing stepis carried out electron-beam radiation.
 25. The method of claim 13,wherein said mixing step is carried out by atomizing and spraying saidprecursor over the substrate in line with the plasma gas.
 26. The methodof claim 18, wherein said mixing step is carried by atomizing andspraying said precursor over the substrate in line with the plasma gas.27. The method of claim 19, wherein said mixing step is carried out byatomizing and spraying said precursor over the substrate in line withthe plasma gas.
 28. The method of claim 20, wherein said mixing step iscarried by atomizing and spraying said precursor over the substrate inline with the plasma gas.
 29. A coated substrate manufactured accordingto the process of claim
 14. 30. A coated substrate manufacturedaccording to the process of claim
 15. 31. A coated substratemanufactured according to the process of claim
 16. 32. A coatedsubstrate manufactured according to the process of claim
 17. 33. Acoated substrate manufactured according to the process of claim
 21. 34.A coated substrate manufactured according to the process of claim 22.35. A coated substrate manufactured according to the process of claim23.
 36. A coated substrate manufactured according to the process ofclaim
 24. 37. A coated substrate manufactured according to the processof claim
 25. 38. A coated substrate manufactured according to theprocess of claim
 26. 39. A coated substrate manufactured according tothe process of claim
 27. 40. A coated substrate manufactured accordingto the process of claim
 28. 41. A coated substrate manufacturedaccording to the process of claim 29.